There are nine of you. You left when you were young, almost too young to remember. You left a planet called Lorien, which was destroyed by Mogadorians, whom ruled the planet next to you, which died out. They came here to take over our planet, but it also died in the battle.
The nine of you scattered once you got on Earth, so you don't know where the others are, and they don't know where you are. This is how we protect ourselves because of the charm that was placed upon us when we left, a charm guaranteeing that we can only be killed in our order of our numbers, so long as we stay apart. If we come together, then the charm is broken.
When or if one of us is killed, in the correct order, a circular scar wraps around the right ankle of those who are still alive. And residing on our left ankle, formed when the Loric charm was first cast, is a small scar identical to the amulet we each wear. The circular charms are another part of the charm. A Warning system so that we know where we stand with each other, and so that we know who has died and which of us is next. The Mogadorians are hunting us, and going to take over Earth. But to protect yourself from them, you have powers, each of you has telekinesis, abs enhancement, but then each of you have different powers. Your powers are called legacies, which you develop when you're under a lot of stress or any other emotion. Or you develop them in time. To help you get through all of this, you have trainers, other known as the people who guide you through your time on Earth, on Lorien they are called a Cepân. And on Lorien you are called a Garde.